Island



Patented May 2, I899.

G. A. WALL.

AUTOMATIC CIRCUIT CLOSER.

(Application filed. Mar. 11, 1898.)

(No Model.)

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0.. PHOTO-LITNO.. WASNINGTON. n. c.

UNITE STATES PATENT OFFICE.

GEORGE A. WALL, OF PROVIDENCE, RIIODE ISLAND.

AUTOMATIC CIRCUIT-CLOSER.

SPECIFICATION forming part of Letters Patent No. 624,27 2, dated May 2,1899.

Application filed March 11, 1898. Serial No. 673,452. (No model.)

To all whom it may concern.-

Be it known that I, GEORGE A. WALL, of Providence, in the State of RhodeIsland, have made certain new and useful Improvements in AutomaticCircuit-Closers; and I do hereby declare that the followingspecification taken in connection with the drawings making a part of thesame, is a full, clear, and exact description thereof.

Figure 1 is an under view of the circuitcloser ready for action, withthe cover removed. Fig. 2 is a side View of the inverted device.

My invention is designed to improve and render more satisfactory in itsoperation the thermostat or automatic fire-alarm set forth and describedin certain Letters Patent of the United States granted to Joel W. WVhiteJuly 31, 1894, and numbered'523,70l; and it consists in the improvedconstruction and arran gement of the releasing mechanism Whereby anearlier action is secured, as hereinafter described. It is desirable incase of fire that an alarm should be given as early as possible. Thiscannot be accomplished satisfactorily by reducing the degree of heatnecessary to a fusion of the solder. If the solder is too soft and tooeasily fused, the thermostat will be likely to operate from any materialincrease in the temperature of the room due to causes other thanaccidental fire. When thermostats are used in connection with automaticfireextinguishers, it is also desirable that the operation of thethermostat, in case of any rapidly-increasing heat, such as a fireproduces, should precede that of the sprinkler to the end thatunnecessary damage by water may be avoided.

In my invention I seek to increase the sensitiveness of the thermostatnot by reducing the fusing-point of the solder, but by'isolating andinsulating the solder as much as possible from the other parts of thedevice, which tend to absorb or Withdraw the heat therefrom.

In my invention, A is a plate or disk, which may be fastened to theceiling by. screws passing through the ears B B. To this plate or disk Athe thermostat G is attached.

D is a central post, around which is coiled a spring E, one end of whichspring is secured through the shell of the thermostat, is secured uponand directly to the outside of such shell by solder. The.securing of theloose end of the spring in this manner does not admit of the freecirculation of the heat coming from the fire around and about thefusible solder, so as to secure the earliest possible action of thealarm.

When the end of the spring is thus attached directly to the shell, itmay be readily ascertained by the use of a sensitive thermometer placedbeside the thermostat that the rapidly-increasing heat will cause suchthermometer to register a temperature much in excess of thepredetermined fusingpoint-of the solder before the solder Will actuallyfuse. action of the metals or other substances of which the shell iscomposed, and the temporary reduction of the force with which the heatattacks the solder. To reduce this withdrawal of the heat to a minimumand render the solder more sensitive to an increase of temperature aboveits predetermined fusing-point, I attach to the outside of-thethermostat-shell a curved frame G, between which and the outside of theshell is an air-space H. To the outside of the frame G, I attach the endof the spring E by means of the solder G, fusible at a low degree ofheat. The end of the spring E may beattached directly to the frame G, orit may be extended by means of a strap J hooked thereto and having acurve similar to that of the frame G, as shown in Fig. 1, the latterconstruction being in my opinion preferable, as it gives more freedom tothe operation or release of the spring and reduces the radiation throughthe spring. Pieces of fiber or other non-conducting materials are usedtoseparate or insulate the feet of the frame G from the shell and areplaced between the frame G and the shell upon the outside and also underthe rivet-heads upon the inside.

It will now be readily seen that with the This result is due to theabsorbing open space H the solder intermediate between the frame G andthe continuation of the spring E will be more completely and evenlysubjected to the action of the heat, while the insulating-pads K K willserve to prevent the absorption of the heat by the other parts of thethermostat whose temperature is less easily increased.

WVhat I claim as my invention, and desire to secure by Letters Patent,is- I 1. In a device of the character described, the combination with athermostat-shell and electrodes, of a frame secured at its opposite endsto the face of the shell and having its intermediate portion raised'topermit the circulation of air around the frame, a spring in operativerelation to the electrodes, and a fuse constituting a connection betweenthe spring and frame, substantially as specified.

2. In a device of the character described, the combination with athermostat-shell and electrodes, of a raised frame carried by the shellin a manner to permit the circulation of air around the frame,insulation intermediate of the frame and shell, a spring in operativerelation with the electrodes and having one end soldered to the frame,substantially as specified.

3. In a device of the character described, the combination with athermostat-shell and electrodes, of an insulated frame raised from theshell to permit the circulation of air around the said frame, a springin operative relation with the electrodes, and a strip of solderconnectingthe spring to the frame and disposed longitudinally withrespect to the latter, substantially as specified.

4. In a device'of the character described, the combination with athermostat-shell and electrodes, of an insulated frame raised from theshell to permit the circulation of air between the parts, a strapsoldered to the frame and a spring connected to the strap and inoperative relation With the electrodes, substantially as specified.

GEORGE A. WVALL.

Witnesses:

WALTER B. VINCENT, FRANK T. EASTON.

